Start work on implementing kitty @ as a static binary using Go

tools/cli/infrastructure.go

@@ -0,0 +1,225 @@
+package cli
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"syscall"
+	"unicode"
+	"unsafe"
+
+	"github.com/fatih/color"
+	runewidth "github.com/mattn/go-runewidth"
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+
+	"kitty"
+)
+
+type Winsize struct {
+	Rows    uint16
+	Cols    uint16
+	Xpixels uint16
+	Ypixels uint16
+}
+
+func GetTTYSize() (Winsize, error) {
+	var ws Winsize
+	f, err := os.OpenFile("/dev/tty", os.O_RDONLY, 0755)
+	if err != nil {
+		return ws, err
+	}
+	fd := f.Fd()
+	retCode, _, errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(fd), uintptr(syscall.TIOCGWINSZ), uintptr(unsafe.Pointer(&ws)))
+	f.Close()
+
+	if int(retCode) == -1 {
+		return ws, errno
+	}
+	return ws, nil
+}
+
+func add_choices(cmd *cobra.Command, flags *pflag.FlagSet, choices []string, name string, usage string) {
+	flags.String(name, choices[0], usage)
+	cmd.Annotations["choices-"+name] = strings.Join(choices, "\000")
+}
+
+func Choices(cmd *cobra.Command, name string, usage string, choices ...string) {
+	add_choices(cmd, cmd.Flags(), choices, name, usage)
+}
+
+func PersistentChoices(cmd *cobra.Command, name string, usage string, choices ...string) {
+	add_choices(cmd, cmd.PersistentFlags(), choices, name, usage)
+}
+
+func key_in_slice(vals []string, key string) bool {
+	for _, q := range vals {
+		if q == key {
+			return true
+		}
+	}
+	return false
+}
+
+func ValidateChoices(cmd *cobra.Command, args []string) error {
+	for key, val := range cmd.Annotations {
+		if strings.HasPrefix(key, "choices-") {
+			allowed := strings.Split(val, "\000")
+			name := key[len("choices-"):]
+			if cval, err := cmd.Flags().GetString(name); err == nil && !key_in_slice(allowed, cval) {
+				return fmt.Errorf("%s: Invalid value: %s. Allowed values are: %s", color.YellowString("--"+name), color.RedString(cval), strings.Join(allowed, ", "))
+			}
+		}
+	}
+	return nil
+}
+
+var title_fmt = color.New(color.FgBlue, color.Bold).SprintFunc()
+var exe_fmt = color.New(color.FgYellow, color.Bold).SprintFunc()
+var opt_fmt = color.New(color.FgGreen).SprintFunc()
+var italic_fmt = color.New(color.Italic).SprintFunc()
+
+func cmd_name(cmd *cobra.Command) string {
+	if cmd.Annotations != nil {
+		parts := strings.Split(cmd.Annotations["exe"], " ")
+		return parts[len(parts)-1]
+	}
+	return cmd.Name()
+}
+
+func print_created_by(root *cobra.Command) {
+	fmt.Println(italic_fmt(root.Annotations["exe"]), opt_fmt(root.Version), "created by", title_fmt("Kovid Goyal"))
+}
+
+func print_with_indent(text string, indent string, screen_width int) {
+	x := len(indent)
+	fmt.Print(indent)
+	in_sgr := false
+	current_word := ""
+
+	print_word := func(r rune) {
+		w := runewidth.StringWidth(current_word)
+		if x+w > screen_width {
+			fmt.Println()
+			fmt.Print(indent)
+			x = len(indent)
+			current_word = strings.TrimSpace(current_word)
+		}
+		fmt.Print(current_word)
+		current_word = string(r)
+		x += w
+	}
+
+	for _, r := range text {
+		if in_sgr {
+			if r == 'm' {
+				in_sgr = false
+			}
+			continue
+		}
+		if r == 0x1b {
+			in_sgr = true
+			continue
+		}
+		if current_word != "" && unicode.IsSpace(r) && r != 0xa0 {
+			print_word(r)
+		} else {
+			current_word += string(r)
+		}
+	}
+	if current_word != "" {
+		print_word(' ')
+		fmt.Print(current_word)
+	}
+	if len(text) > 0 {
+		fmt.Println()
+	}
+}
+
+func show_usage(cmd *cobra.Command) error {
+	ws, tty_size_err := GetTTYSize()
+	screen_width := 80
+	if tty_size_err == nil && ws.Cols < 80 {
+		screen_width = int(ws.Cols)
+	}
+	fmt.Println(title_fmt("Usage")+":", exe_fmt(cmd.Annotations["exe"]), cmd.Use)
+	fmt.Println()
+	if len(cmd.Long) > 0 {
+		print_with_indent(cmd.Long, "", screen_width)
+	} else if len(cmd.Short) > 0 {
+		print_with_indent(cmd.Short, "", screen_width)
+	}
+	if cmd.HasAvailableSubCommands() {
+		fmt.Println()
+		fmt.Println(title_fmt("Commands") + ":")
+		for _, child := range cmd.Commands() {
+			fmt.Println(" ", opt_fmt(cmd_name(child)))
+			print_with_indent(child.Short, "    ", screen_width)
+		}
+		fmt.Println()
+		print_with_indent("Get help for an individual command by running:", "", screen_width)
+		fmt.Println("   ", cmd.Annotations["exe"], italic_fmt("command"), "-h")
+	}
+	if cmd.HasAvailableFlags() {
+		options_title := cmd.Annotations["options_title"]
+		if len(options_title) == 0 {
+			options_title = "Options"
+		}
+		fmt.Println()
+		fmt.Println(title_fmt(options_title) + ":")
+		flag_set := cmd.LocalFlags()
+		flag_set.VisitAll(func(flag *pflag.Flag) {
+			fmt.Print(opt_fmt("  --" + flag.Name))
+			if flag.Shorthand != "" {
+				fmt.Print(", ", opt_fmt("-"+flag.Shorthand))
+			}
+			defval := ""
+			switch flag.Value.Type() {
+			default:
+				defval = fmt.Sprintf("[=%s]", italic_fmt(flag.DefValue))
+			case "bool":
+			case "count":
+			}
+			if defval != "" {
+				fmt.Print(" ", defval)
+			}
+			fmt.Println()
+			if flag.Name == "help" {
+				fmt.Println("   ", "Print this help message")
+				fmt.Println()
+				return
+			}
+			for _, line := range strings.Split(flag.Usage, "\n") {
+				print_with_indent(line, "    ", screen_width)
+			}
+			if cmd.Annotations["choices-"+flag.Name] != "" {
+				fmt.Println("    Choices:", strings.Join(strings.Split(cmd.Annotations["choices-"+flag.Name], "\000"), ", "))
+			}
+			fmt.Println()
+		})
+	}
+	if cmd.HasParent() {
+		cmd.VisitParents(func(cmd *cobra.Command) {
+			if !cmd.HasParent() {
+				print_created_by(cmd)
+			}
+		})
+	} else {
+		print_created_by(cmd)
+	}
+
+	return nil
+}
+
+func CreateCommand(cmd *cobra.Command, exe string) *cobra.Command {
+	cmd.Annotations = make(map[string]string)
+	cmd.Annotations["exe"] = exe
+	return cmd
+}
+
+func Init(root *cobra.Command) {
+	root.Version = kitty.VersionString
+	root.PersistentPreRunE = ValidateChoices
+	root.SetUsageFunc(show_usage)
+	root.SetHelpTemplate("{{.UsageString}}")
+}